H2SO4-Mediated Intramolecular Cyclization of N-Arylated Homoallylamines: A Solvent-Free, Atom- and Step-Economical Synthesis of Tetrahydro-1-benzazepines

The biologically important tetrahydro-1-benzazepine skeleton was conveniently constructed from N-arylated homoallylamines through H2SO4-mediated intramolecular cyclization. The advantages of this transformation include mild reaction conditions, experimental simplicity, its solvent- and metal-free, atom- and step-economical nature, and the use of a readily available, cheap, and nontoxic mediator.